Semiconductor Device with Partial EMI Shielding Removal Using Laser Ablation

ABSTRACT

A semiconductor device has a substrate. A first component and second component are disposed over the substrate. The first component includes an antenna. A lid is disposed over the substrate between the first component and second component. An encapsulant is deposited over the substrate and lid. A conductive layer is formed over the encapsulant and in contact with the lid. A first portion of the conductive layer over the first component is removed using laser ablation.

CLAIM TO DOMESTIC PRIORITY

The present application is a continuation of U.S. patent applicationSer. No. 16/991,370, filed Aug. 12, 2020, which is a continuation ofU.S. patent application Ser. No. 16/234,156, now U.S. Pat. No.10,784,210, filed Dec. 27, 2018, which applications are incorporatedherein by reference.

FIELD OF THE INVENTION

The present invention relates in general to semiconductor devices and,more particularly, to semiconductor devices, and methods of formingsemiconductor devices, with electromagnetic interference (EMI) shieldinglayers that are partially removed using laser ablation.

BACKGROUND OF THE INVENTION

Semiconductor devices are commonly found in modern electronic products.Semiconductor devices perform a wide range of functions such as signalprocessing, high-speed calculations, transmitting and receivingelectromagnetic signals, controlling electronic devices, transformingsunlight to electricity, and creating visual images for televisiondisplays. Semiconductor devices are found in the fields ofcommunications, power conversion, networks, computers, entertainment,and consumer products. Semiconductor devices are also found in militaryapplications, aviation, automotive, industrial controllers, and officeequipment.

Semiconductor devices commonly include some circuitry to process radiofrequency (RF) signals. Recent technological advances allow for highspeed digital and RF semiconductor packages integrated with small sizes,low heights, high clock frequencies, and good portability usingsystem-in-package (SiP) technology. SiP devices include multiplesemiconductor components, e.g., semiconductor die, semiconductorpackages, integrated passive devices, and discrete active or passiveelectrical components, integrated together in a single semiconductorpackage.

FIG. 1 illustrates a prior art SiP device 30. SiP device 30 includes aplurality of components disposed on a PCB or other substrate 32.Substrate 32 includes one or more insulating layers 34 with conductivelayers 36 formed over, between, and through insulating layers 34.

Semiconductor die 40 is integrated as part of SiP device 30.Semiconductor die 40 includes an active surface 42 with contact pads 44formed over the active surface. Solder bumps 46 are used to electricallyand mechanically couple contact pads 44 of semiconductor die 40 toconductive layer 36 of substrate 32. Semiconductor die 40 iselectrically coupled to semiconductor package 50 through conductivelayers 36.

Semiconductor package 50 includes semiconductor die 52 to provide activefunctionality. Semiconductor die 52 has contact pads 54 over an activesurface of the semiconductor die. Semiconductor die 52 is disposed overa die pad of leadframe 56 and coupled to contacts or leads of theleadframe by bond wires 57. Semiconductor die 52, bond wires 57, andleadframe 56 are molded in encapsulant 58 prior to integration into SiPdevice 30. Once completed, semiconductor package 50 is mounted onsubstrate 32 with solder 59 used for mechanical and electrical coupling.In one embodiment, solder 59 is a solder paste printed onto substrate 32prior to mounting of semiconductor package 50.

A second encapsulant 60 is deposited over semiconductor die 40,semiconductor package 50, and substrate 32 after integration toenvironmentally protect SiP device 30. Solder bumps 62 are disposed onthe opposite side of substrate 32 from semiconductor die 40 andsemiconductor package 50. Bumps 62 are subsequently used to mount SiPdevice 30 onto the substrate of a larger electronic device. SiP device30 includes a plurality of semiconductor devices that operate togetherto achieve a desired electrical functionality.

Semiconductor devices are often susceptible to electromagneticinterference (EMI), radio frequency interference (RFI), harmonicdistortion, or other inter-device interference, such as capacitive,inductive, or conductive coupling, also known as cross-talk, which caninterfere with their operation. The high-speed switching of digitalcircuits also generates interference.

Because of the high speed digital and RF circuits in SiP device 30,shielding from electromagnetic interference (EMI) is important.Conformal EMI shielding has emerged as a preferred method to reduce theeffects of EMI. EMI from nearby devices hitting SiP device 30 can causemalfunctions within the SiP device's components. EMI from SiP device 30may also cause malfunctions in nearby devices. FIG. 1 illustrates aconformal EMI shield 64. EMI shield 64 is a thin layer of metal formedby sputtering that is conformally coated over the top and side surfacesof SiP device 30 after encapsulant 60 is deposited. EMI shield 64reduces the magnitude of EMI radiation entering and exiting SiP device30 to reduce interference. In some embodiments, EMI shield 64 is coupledto ground through conductive layers 36 in substrate 32 that extend tothe edge of the substrate.

EMI shield 64 provides a reduction in EMI interference. However,conformal coating EMI shield 64 over the entirety of SiP device 30causes problems for devices or modules in the SiP device that need toact as a transceiver antenna. EMI shield 64 reduces the magnitude of allelectromagnetic radiation, including radiation desired for communicationor other purposes. To transmit and receive using an antenna,semiconductor die 40 or semiconductor package 50 must be coupled to aseparate element of the electronic device with an antenna outside of EMIshield 64. However, having transceiver components integrated within aSiP device along with other components that benefit from EMI protectionwould allow further improvements in speed, size, and power requirementsof electronic devices. Therefore, a need exists for partial EMIshielding of semiconductor packages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a SiP device with a conformally appliedelectromagnetic interference (EMI) shielding layer;

FIGS. 2 a-2 h illustrate a process of forming a SiP device with EMIshielding;

FIGS. 3 a-3 d illustrate a process of partially removing the EMIshielding from a plurality of SiP devices on a carrier using a singlelaser;

FIGS. 4 a and 4 b illustrate the SiP device formed with partialshielding;

FIGS. 5 a and 5 b illustrate a process of partially removing EMIshielding from a plurality of units using a multi-laser setup;

FIGS. 6 a-6 d illustrate a process of partially removing the EMIshielding from a single freely rotating SiP device using a single laser;

FIG. 7 illustrates a process of partially removing the EMI shieldingfrom a single unit rotating about only one axis;

FIGS. 8 a-8 f illustrate a process of partially removing EMI shieldingusing a combination of a film mask and laser removal;

FIGS. 9 a-9 c illustrate alternative configurations for the removal ofEMI shielding; and

FIGS. 10 a and 10 b illustrate integrating a SiP device into anelectronic device.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention is described in one or more embodiments in thefollowing description with reference to the figures, in which likenumerals represent the same or similar elements. While the invention isdescribed in terms of the best mode for achieving the invention'sobjectives, it will be appreciated by those skilled in the art that itis intended to cover alternatives, modifications, and equivalents as maybe included within the spirit and scope of the invention as defined bythe appended claims and their equivalents as supported by the followingdisclosure and drawings. The term “semiconductor die” as used hereinrefers to both the singular and plural form of the words, andaccordingly, can refer to both a single semiconductor device andmultiple semiconductor devices.

FIG. 2 a is a cross-sectional view of a panel 100 of SiP devicesseparated by saw streets 102 prior to forming of a partial EMI shieldand singulation into individual SiP devices. Two SiP devices areillustrated, but hundreds or thousands of SiP device are commonly formedin a single panel using the same steps illustrated below. Panel 100 isformed over a substrate 110, similar to substrate 32 in FIG. 1 .Substrate 110 includes one or more insulating layers 112 interleavedwith one or more conductive layers 114. Insulating layer 112 is a coreinsulating board in one embodiment, with conductive layers 114 patternedover the top and bottom surfaces, e.g., a copper-clad laminatesubstrate. Conductive layers 114 also include conductive viaselectrically coupled through insulating layers 112. Substrate 110 caninclude any number of conductive and insulating layers interleaved overeach other. A solder mask or passivation layer can be formed over eitherside of substrate 110.

Solder bumps 116 are formed on contact pads of conductive layer 114 overthe bottom surface of substrate 110. Bumps 116 are optionally formed ata later processing step. Other types of interconnect structures are usedin other embodiments for integration of the SiP devices into anelectronic device, such as stud bumps, conductive pins, copper pillars,land grid array (LGA) pads, or wire bonds.

Any suitable type of substrate or leadframe is used for substrate 110 inother embodiments. In one embodiment, panel 100 is formed over asacrificial substrate 110 that is later removed. Removing thesacrificial substrate exposes interconnect structures on theencapsulated devices, e.g., bumps 46 on semiconductor die 124, forsubsequent integration into the larger system.

Any components desired to implement the intended functionality of theSiP devices are mounted to or disposed over substrate 110 andelectrically connected to conductive layers 114. FIG. 2 a illustratessemiconductor package 50 and semiconductor die 124 mounted on substrate110 as an example. Semiconductor die 124 is a transceiver device thatuses antenna 128 to convert between an electromagnetic radiation signalsent or received over the airwaves and an electrical signal within thesemiconductor die. The transceiver functionality of semiconductor die124 will be facilitated by not having a conformal EMI shielding layerformed over antenna 128, which could block desirable signals. On theother hand, semiconductor package 50 is an example device that willbenefit from EMI shielding.

In one embodiment, semiconductor die 124 is a radar device used forobject detection in self-driving vehicles, and semiconductor package 50includes memory and logic circuits to support the radar functionality.In other embodiments, any desired components can be incorporated into aSiP device. The components can include any combination of any type ofsemiconductor package, semiconductor die, integrated passive device,discrete active or passive components, or other electrical components.

The components in each SiP device, e.g., semiconductor die 124 andsemiconductor package 50, are mounted on and connected to substrate 110by a suitable interconnect structure, e.g., solder bumps 46, and thenencapsulated. An encapsulant or molding compound 130 is deposited oversemiconductor die 124, semiconductor package 50, and substrate 110 usinga paste printing, compressive molding, transfer molding, liquidencapsulant molding, vacuum lamination, spin coating, or anothersuitable applicator. Encapsulant 130 can be polymer composite material,such as epoxy resin, epoxy acrylate, or any suitable polymer with orwithout filler. Encapsulant 130 is non-conductive, provides structuralsupport, and environmentally protects the SiP devices from externalelements and contaminants.

In FIG. 2 b , a trench 140 is formed through each SiP device betweensemiconductor die 124 and semiconductor package 50. Trench 140 is formedby chemical etching with a photolithographic mask, laser ablation, sawcutting, reactive ion etching, or another suitable trenching process. Inone embodiment, trench 140 extends continuously for an entire length ofpanel 100 into and out of the page of FIG. 2 b . Trench 140 is shorterin other embodiments, e.g., only formed directly between semiconductordie 124 and semiconductor package 50 and not extending to the edges ofthe SiP devices. Trench 140 is formed completely through encapsulant 130down to substrate 110. In some embodiments, a portion of conductivelayer 114 is exposed within trench 140. Conductive layer 114 can bepatterned to include a strip extending for the length of trench 140 toreduce electrical resistance between the conductive layer and conductivematerial subsequently deposited into the trench.

FIG. 2 c illustrates a partial cross-section of panel 100. Trenches 140are filled with conductive material to form lids 150. Lid 150 is formedusing any suitable metal deposition technique. Lid 150 can be formed byfilling trench 140 with a conductive ink or paste, or plating conductivematerial within the trench. In other embodiments, lid 150 is pre-formedand inserted into trench 140. Lid 150 is a metal layer extending betweensemiconductor die 124 and package 50 to reduce the magnitude of EMIdirectly radiating from antenna 128 toward package 50, or vice versa. Insome embodiments, lid 150 is electrically coupled to a ground nodethrough conductive layer 114 and bumps 116 to aid in EMI blockingcapability. In other embodiments, lid 150 reduces EMI without aconnection to conductive layer 114 or a ground node.

FIG. 2 d illustrates a perspective view of a portion of panel 100 havingeight SiP devices formed at once. Each of the eight SiP devices includesa lid 150 splitting the device into two distinct regions. Lid 150 isillustrated as being halfway between adjacent saw streets 102. However,the lid can form any desired size and shape of partition for EMIshielding. Each column or row of devices shares a lid 150 in common, astrench 140 and lid 150 are formed for an entire length or width of panel100. In other embodiments, each device has a separate lid 150 that mayor may not extend to saw streets 102.

In FIG. 2 e , panel 100 is singulated at saw streets 102 using a sawblade, water jet, or laser cutting tool 154 to cut through encapsulant130 and substrate 110 and separate each of the devices into anindividual SiP device 156 as shown in FIG. 2 f . Singulation creates agap between each unit where saw streets 102 were located. The gap allowsdeposition of a conformal shielding layer over side surfaces of SiPdevices 156 in FIGS. 2 g and 2 h , which show two different views of thesame processing step.

Conformal shielding layer 160 is formed over SiP devices 156 andcompletely covers top and side surfaces of each SiP device. Shieldinglayer 160 is formed by spray coating, plating, sputtering, or any othersuitable metal deposition process. Shielding layer 160 can be formedfrom copper, aluminum, iron, or any other suitable material for EMIshielding. In some embodiments, panel 100 is disposed on a carrier withan optional thermal release or interface layer during singulation inFIG. 2 e . The singulated SiP devices 156 remain on the same carrier forapplication of shielding layer 160. Therefore, the space betweenadjacent SiP devices 156 during forming of shielding layer 160 isequivalent to the width of the saw kerf of cutting tool 154. Thethickness of shielding layer 160 is low enough that the shielding layersof adjacent SiP devices 156 do not touch and the packages remainsingulated on the carrier. In other embodiments, SiP devices 156 aredisposed on a separate carrier after singulation and prior to formingshielding layer 160.

Shielding layer 160 completely covers every exposed surface of SiPdevice 156, including the top and all four side surfaces. All exposedsurfaces of encapsulant 130 are coated in the conductive material informing shielding layer 160. The bottom surface of SiP device 156 withsubstrate 110 and bumps 116 is normally not covered by shielding layer160, either because the sputtering method is from the top-down and onlycovers sideways or upward facing surfaces, or because an interface layeron the carrier fully covers the bottom surface and operates as a mask.

Shielding layer 160 is formed directly contacting top and side surfacesof lid 150 to form a continuous EMI shield. Each SiP device 156 is splitinto two sides by lid 150: open side 156 a and shielded side 156 b. Openside 156 a is referred to as the open side because the open side willhave shielding layer 160 at least partially removed so that componentsare “open” to send and receive radio signals. Any devices that desirablyemit or receive electromagnetic radiation, e.g., semiconductor die 124,are placed within open side 156 a. Any devices that are to be protectedfrom EMI by shielding, e.g., semiconductor package 50, are placed withinshielded side 156 b. The devices on open side 156 a and shielded side156 b can be electrically coupled to each other across the boundarycreated by lid 150 through conductive layers 114, or by an underlyingsubstrate of a larger electronic device that SiP device 156 isintegrated into.

FIGS. 3 a-3 d illustrate a method of removing shielding layer 160 usinga single laser 180 directed from above the units. In one embodiment,laser 180 is part of an assembly with scanner 182. Laser 180 and scanner182 are computer controlled and able to move in a plane parallel to thecarrier that SiP devices 156 are placed on. The controller moves scanner182 above a particular SiP device 156, and then, in FIGS. 3 a and 3 b ,operates the laser assembly to remove shielding layer 160 on the topsurface of open side 156 a. In other embodiments, laser 180 and scanner182 remain static, and the carrier holding SiP devices 156 is movedunder the laser assembly to advance the ablation process to a differentSiP device.

Scanner 182 receives a light beam from laser 180 and guides the beamdown to a SiP device 156. Scanner 182 moves the laser beam around toevenly hit all areas of shielding layer 160 to be removed. Scanner 182can move the beam from laser 180 in any suitable scanning pattern toremove shielding layer 160 from the desired surface area, e.g., an “S”scanning pattern or a fractal scanning pattern.

A two-step removal process is used for shielding layer 160 on the topsurface of open side 156 a. First, shielding layer 160 is removed usinga metal peeling process, whereby the beam from laser 180 is defocusedand the energy peels off the desired portion of shielding layer 160.Metal peeling is a type of laser ablation. After the peeling processremoves shielding layer 160 where desired, soft laser ablation isperformed with laser 180 set at a low power level as a cleaning processto remove remaining metal residue. In other embodiments, a single-steplaser ablation process is performed on the top surface with laser 180.

Only the top surface of SiP devices 156, opposite substrate 110, haveshielding layer removed in FIGS. 3 a and 3 b . Shielding layer 160 isonly partially removed to remain in electrical and physical contact withthe top of lid 150, thus maintaining a continuous shield around thesides and over the top of shielded side 156 b. In some embodiments, SiPdevices 156 are completed after processing is complete in FIGS. 3 a and3 b . Opening only the top of open side 156 a is sufficient for thedesired use of SiP devices 156 in some embodiments.

FIGS. 3 c and 3 d show further processing to remove shielding layer 160over side surfaces of open side 156 a. The assembly of laser 180 andscanner 182 is again moved from unit to unit to perform laser ablationon the side surfaces of SiP devices 156. In another embodiment,different lasers are used for ablation of the top and side surfaces. Theprocessing of both top and side surfaces can be performed on eachindividual SiP device 156 before moving on to another device, or the topsurfaces of all SiP devices 156 can be processed prior to any of theside surfaces.

Scanner 182 is positioned in the plane of a side surface of an open side156 a and used to direct a beam from laser 180 down the height of theside surface. The beam of laser 180 ablates shielding layer 160 for theentire height of SiP device 156 where the beam is directed. The beam oflaser 180 is swept across the side surface by scanner 182 to fullyremove shielding layer 160 from the side surface. In some embodiments, aportion of encapsulant 130 and substrate 110 are removed along withshielding layer 160.

Once all desired portions of shielding layer 160 are removed from sidesurfaces of a SiP device 156, scanner 182 is moved to the next SiPdevice to be processed. In some embodiments, scanner 182 is repositionedfor each individual side surface of a SiP device 156. To fully removeshielding layer 160 from over open side 156 a, the beam of laser 180 isguided in the shape of a bracket character, i.e., 1, cutting verticallythrough the edge of SiP device 156. Shielding layer 160 remainsphysically contacting the sides of lid 150 to maintain continuousshielding all the way around closed side 156 b.

FIGS. 4 a and 4 b show a SiP device 156 after shielding layer 160 isremoved from top and side surfaces of open side 156 a. Package 50 isfully EMI shielded by shielding layer 160 on the top and three sides andlid 150 on the fourth side. Shielding layer 160 contacts lid 150 for anentire height and width of the lid. Semiconductor die 124 has shieldinglayer 160 cleared on side and top surfaces of SiP module 156, and istherefore able to send and receive radio signals while package 50 isfully protected.

FIGS. 5 a and 5 b illustrate a method of partially removing EMIshielding layer 160 using a dual laser setup. In FIG. 5 a , SiP devices156 are disposed on a carrier 190 after shielding layer 160 is formed inFIG. 2 h . Carrier 190 is similar to the carrier that panel 100 isdisposed on for singulation and plating of shielding layer 160. However,SiP devices 156 are disposed on a separate carrier to allow the devicesto be more spread out.

In FIG. 5 b , a dual laser system is used to partially remove EMI shield160 over open side 156 a. Laser 200 emits a beam through scanner 202,and laser 204 emits a beam through scanner 206. The lasers are orientedon opposite sides of a SiP device 156 from each other. Laser 200 is ableto hit the surface of SiP device 156 facing toward the viewer of FIG. 5b , and laser 204 is able to hit the surface of the SiP device facingaway from the viewer. Both lasers 200 and 204 are able to hit thesurfaces of SiP device 156 oriented to the right and the top in FIG. 5 b. Lasers 200 and 204 can operate simultaneously to increase throughput.

In combination, lasers 200 and 204 are able to hit all portions ofshielding layer 160 on open side 156 a. Scanners 202 and 206 sweepacross the surfaces of SiP devices 156 in any suitable pattern to removeshielding layer 160 over open side 156 a by laser ablation. Each laserremoves approximately half of the total removed area of shielding layer160. After all desired areas of shielding layer 160 have been removed byablation for a given SiP device 156, carrier 190 is moved so that adifferent SiP device is disposed between lasers 200 and 204. Thecompleted devices look substantially the same as SiP devices 156 inFIGS. 4 a and 4 b.

FIGS. 6 a-6 d illustrate a method of removing EMI shielding layer 160over open side 156 a using one laser operating on a single package at atime. For ablation, SiP devices 156 are picked up one at a time by apick and place machine, or another tool capable of freely rotating theSiP devices around any and all axes. In FIG. 6 a , SiP module 156 isheld under laser 210 and scanner 212 with top surface 220 orientedtoward the laser. Scanner 212 moves the laser beam around to fullyablate shielding layer 160 from the portion of top surface 220 over openside 156 a. A combination of metal peeling and soft laser ablation isused in some embodiments. Top surface 220 of an entire panel of unitscan be ablated prior to the units being picked up by the pick and placemachine, just as in FIG. 3 b.

In FIG. 6 b , the pick and place machine turns package 156 to orientside surface 222 toward laser 210. Scanner 212 guides the beam fromlaser 210 to cover surface 222 and fully remove shielding layer 160 fromthe surface. Surface 222 is oriented parallel to the plane of lid 150,so fully removing shielding layer 160 from surface 222 does not exposelid 150. In other embodiments, a portion of shielding layer 160 is lefton surface 222.

In FIG. 6 c , SiP device 156 is again turned by the pick and placemachine, now with side surface 224 oriented toward laser 210. The beamof laser 210 is scanned across the portion of surface 224 over open side156 a to remove shielding layer 160 by ablation. Shielding layer 160 isremoved up to the edge of open side 156 a, where the shielding layercontacts lid 150. Shielding layer 160 remains fully contacting lid 150to improve EMI blocking. In other embodiments, lid 150 is fully orpartially exposed.

Finally, in FIG. 6 d , SiP device 156 is turned with side surface 226oriented toward laser 210. Shielding layer 160 is removed from surface226 over open side 156 a. All of the side surfaces 222-226 can haveshielding layer 160 removed by a combination of metal peeling and softlaser ablation, or by a single ablation step. With surfaces 220-226 ofSiP device 156 all ablated over open side 156 a, SiP device 156 appearssimilarly to in FIGS. 4 a and 4 b . While surfaces 220-226 areillustrated as being ablated in one specific order, SiP device 156 isrotated in any suitable pattern to ablate the surfaces in any desiredorder.

FIG. 7 shows a method of laser ablation that uses a single laseroperating on a single SiP device 156. In FIG. 7 , a method of holdingSiP device 156 is used that only allows rotation of the device around asingle axis 230 oriented vertically. First, shielding layer 160 isremoved from top surface 220 using ablation by laser 240 and a scanner,similar to the step shown in FIG. 6 a . After top surface 220 isablated, the scanner is actuated out of the path of the laser beam, andthe beam from laser 240 is reflected to scanner 242 by mirror 244.Scanner 242 is disposed to the side of SiP device 156 to allow thescanner to guide the beam from laser 240 to side surfaces of the SiPdevice.

In FIG. 7 , ablation began with surface 224 oriented toward scanner 242.Shielding layer 160 was removed from surface 224, and then SiP device156 was rotated about axis 230 so that surface 222 is oriented towardthe scanner. Scanner 242 scans the beam from laser 240 to removeshielding layer 160 from surface 222. In the illustrated embodiment,scanner 242 uses an S pattern with vertical sweeps going from left toright. The laser is about halfway completed with ablation of surface222. Once ablation of shielding layer 160 is complete on surface 222,SiP device 156 will be rotated about axis 230 again to perform ablationon surface 226. In some embodiments, scanner 242 is used to scan thelaser beam in the vertical direction only, and scanning in thehorizontal direction is performed by rotating SiP module 156 about axis230. Once ablation is complete on all desired surfaces, SiP module 156appears substantially the same as in FIGS. 4 a and 4 b.

FIGS. 8 a-8 f illustrate a method of combining a film mask with laserablation to remove shielding layer 160 over open side 156 a. Using afilm mask to perform partial shielding layer removal is explained morethoroughly in U.S. patent application Ser. No. 16/116,485, filed Aug.29, 2018, which is incorporated herein by reference. FIGS. 8 a and 8 bshow a cross-section and perspective view, respectively, of panel 100with film 252 disposed over open side 156 a of each SiP device 156. Film252 is an adhesive tape, metal foil film, metal foil tape, polyimidefilm, or any other suitable film mask. A metal, plastic, or siliconemask is used for film 252 in other embodiments.

Any of the film 252 options can include adhesive to provide a mechanicalattachment of the film to encapsulant 130. The adhesive can beultraviolet (UV) release, thermal release, or otherwise configured toallow for convenient removal of film 252. Film 252 can also be anysuitable insulating, passivation, or photoresist layer deposited by anyappropriate thin film deposition technique. Film 252 is applied over thetop surface of panel 100 on encapsulant 130 and runs in parallel withlids 150. Lids 150 remain exposed from film 252 so that shielding layer160 will contact the lids to form a continuous EMI shield.

Film 252 is applied in strips over open side 156 a prior to singulationof panel 100 into individual units. In other embodiments, film 252 isapplied after singulation. Film 252 extends along the entire length ofpanel 100 in parallel with lid 150, and perpendicularly across panel 100from each lid to an adjacent saw street 102. Therefore, the open side156 a of each SiP device 156 is fully covered by film 252. In otherembodiments, only a portion of each open side 156 a is covered by film252. Film 252 could be applied as a small patch of film directly overeach semiconductor die 124 without extending to lid 150 or any sawstreet 102.

In FIGS. 8 c and 8 d , shielding layer 160 is deposited in substantiallythe same manner as in FIG. 2 h . The entirety of SiP devices 156,including film 252, is covered in shielding layer 160. In FIGS. 8 e and8 f , shielding layer 160 is removed from the top surface of open side156 a by removing film 252 rather than with laser peeling or laserablation as in the above embodiments. Mechanical peeling of film 252also removes the portion of shielding layer 160 on top of the film, thuscreating an opening in the shielding layer over open side 156 a.Shielding layer 160 is then removed over side surfaces of SiP device 156using any of the above laser ablation methods.

FIGS. 9 a-9 c show three non-limiting configurations for removal ofshielding layer 160. While the above embodiments all show shieldinglayer 160 completely removed over all surfaces of open side 156 a, someembodiments will benefit from having the shielding layer only partiallyremoved. Leaving a portion of shielding layer 160 over open side 156 acan help guide broadcasts from the open side, and help reduce EMI inopen side 156 a coming from certain directions.

In FIG. 9 a , shielding layer 160 is removed only from the center of topsurface 220 and side surface 222, but not the ends of those surfaces. Inaddition, shielding layer 160 is not removed from side surfaces 224 and226. The portions of shielding layer 160 remaining at the ends of openside 156 a protect the open side from EMI while still allowingintentionally transmitted signals through.

FIG. 9 b shows shielding layer 160 remaining on only the middle portionof surfaces 220 and 222, while being removed at the ends and on surfaces224 and 226. FIG. 9 c shows shielding layer 160 removed at only one endof open side 156 a. Shielding layer 160 can be removed from over openside 156 a in any desired pattern.

FIGS. 10 a and 10 b illustrate incorporating SiP device 156 into anelectronic device after forming a partial shielding layer by any of theabove described processes. FIG. 10 a illustrates a partial cross-sectionof SiP device 156 from FIGS. 4 a and 4 b mounted onto a PCB or othersubstrate 342 as part of an electronic device. Bumps 116 are reflowedonto conductive layer 344 of PCB 342 to physically attach andelectrically connect SiP device 156 to the PCB. In other embodiments,thermocompression or other suitable attachment and connection methodsare used. Rather than bumps, interconnect can be provided through studbumps, lands, pins, bond wires, or any other suitable interconnectstructure. In some embodiments, an adhesive or underfill layer is usedbetween SiP device 156 and PCB 342. Semiconductor die 124 and package 50are electrically coupled to conductive layer 344 and each other throughconductive layer 114 and bumps 116.

FIG. 10 b illustrates electronic device 340 including PCB 342 with aplurality of semiconductor packages mounted on a surface of the PCB,including SiP device 156. Electronic device 340 can have one type ofsemiconductor package, or multiple types of semiconductor packages,depending on the application.

Electronic device 340 can be a stand-alone system that uses thesemiconductor packages to perform one or more electrical functions.Alternatively, electronic device 340 can be a subcomponent of a largersystem. For example, electronic device 340 can be part of a tabletcomputer, cellular phone, digital camera, communication system, or otherelectronic device. Electronic device 340 can also be a graphics card,network interface card, or other signal processing card that is insertedinto a computer. The semiconductor packages can include microprocessors,memories, ASICs, logic circuits, analog circuits, RF circuits, discreteactive or passive devices, or other semiconductor die or electricalcomponents.

In FIG. 10 b , PCB 342 provides a general substrate for structuralsupport and electrical interconnection of the semiconductor packagesmounted on the PCB. Conductive signal traces 344 are formed over asurface or within layers of PCB 342 using evaporation, electrolyticplating, electroless plating, screen printing, or other suitable metaldeposition process. Signal traces 344 provide for electricalcommunication between the semiconductor packages, mounted components,and other external systems or components. Traces 344 also provide powerand ground connections to the semiconductor packages as needed.

In some embodiments, a semiconductor device has two packaging levels.First level packaging is a technique for mechanically and electricallyattaching the semiconductor die to an intermediate substrate. Secondlevel packaging involves mechanically and electrically attaching theintermediate substrate to PCB 342. In other embodiments, a semiconductordevice may only have the first level packaging where the die ismechanically and electrically mounted directly to PCB 342.

For the purpose of illustration, several types of first level packaging,including bond wire package 346 and flipchip 348, are shown on PCB 342.Additionally, several types of second level packaging, including ballgrid array (BGA) 350, bump chip carrier (BCC) 352, LGA 356, multi-chipmodule (MCM) 358, quad flat non-leaded package (QFN) 360, and waferlevel chip scale package (WLCSP) 366 are shown mounted on PCB 342 alongwith SiP device 156. Conductive traces 344 electrically couple thevarious packages and components disposed on PCB 342 to SiP device 156,giving use of the components within the SiP device to other componentson the PCB.

Depending upon the system requirements, any combination of semiconductorpackages, configured with any combination of first and second levelpackaging styles, as well as other electronic components, can beconnected to PCB 342. In some embodiments, electronic device 340includes a single attached semiconductor package, while otherembodiments call for multiple interconnected packages. By combining oneor more semiconductor packages over a single substrate, manufacturerscan incorporate pre-made components into electronic devices and systems.Because the semiconductor packages include sophisticated functionality,electronic devices can be manufactured using less expensive componentsand a streamlined manufacturing process. The resulting devices are lesslikely to fail and less expensive to manufacture resulting in a lowercost for consumers.

While one or more embodiments of the present invention have beenillustrated in detail, the skilled artisan will appreciate thatmodifications and adaptations to those embodiments may be made withoutdeparting from the scope of the present invention as set forth in thefollowing claims.

What is claimed:
 1. A method of making a semiconductor device,comprising: providing a semiconductor package comprising an encapsulantand an electromagnetic interference (EMI) shield exposed from theencapsulant; forming a conductive layer over the encapsulant and incontact with the EMI shield; and removing a first portion of theconductive layer, wherein the portion of the conductive layer extendsover a plurality of surfaces of the semiconductor package.
 2. The methodof claim 1, further including removing the first portion of theconductive layer using a plurality of laser ablation processes.
 3. Themethod of claim 1, wherein removing the first portion of the conductivelayer includes a metal peeling process.
 4. The method of claim 1,wherein the plurality of laser ablation processes occur simultaneously.5. The method of claim 1, further including rotating the semiconductorpackage while removing the first portion of the conductive layer.
 6. Themethod of claim 1, further including removing a second portion of theconductive layer discontinuous with the first portion of the conductivelayer.
 7. A method of making a semiconductor device, comprising:providing a semiconductor package including a conductive layer formedover the semiconductor package; and removing a first portion of theconductive layer, wherein the portion of the conductive layer extendsover a plurality of surfaces of the semiconductor package.
 8. The methodof claim 7, further including removing the first portion of theconductive layer using a plurality of laser ablation processes.
 9. Themethod of claim 7, wherein removing the first portion of the conductivelayer includes a metal peeling process.
 10. The method of claim 7,wherein the plurality of laser ablation processes occur simultaneously.11. The method of claim 7, further including rotating the semiconductorpackage while removing the first portion of the conductive layer. 12.The method of claim 7, further including removing a second portion ofthe conductive layer discontinuous with the first portion of theconductive layer.
 13. The method of claim 7, wherein the semiconductorpackage includes an electromagnetic interference (EMI) shield in contactwith the conductive layer.
 14. A method of making a semiconductordevice, comprising: providing a semiconductor package comprising aconductive layer formed over the semiconductor package; removing a firstportion of the conductive layer using laser ablation; and removing asecond portion of the conductive layer using laser ablation.
 15. Themethod of claim 14, wherein the first portion of the conductive layer isremoved over a first surface of the semiconductor package and the secondportion of the conductive layer is removed over a second surface of thesemiconductor package different from the first surface.
 16. The methodof claim 15, wherein the first portion of the conductive layer andsecond portion of the conductive layer are each removed using a laseroriented perpendicular to the first surface and parallel to the secondsurface.
 17. The method of claim 14, further including removing thefirst portion of the conductive layer simultaneously with removing thesecond portion of the conductive layer.
 18. The method of claim 14,further including rotating the semiconductor package after removing thefirst portion of the conductive layer and before removing the secondportion of the conductive layer.
 19. The method of claim 14, wherein thefirst portion of the conductive layer and second portion of theconductive layer are continuous with each other.
 20. A method of makinga semiconductor device, comprising: providing a semiconductor packageincluding a conductive layer over the semiconductor package; removing afirst portion of the conductive layer; and removing a second portion ofthe conductive layer.
 21. The method of claim 20, wherein the firstportion of the conductive layer is removed over a first surface of thesemiconductor package and the second portion of the conductive layer isremoved over a second surface of the semiconductor package differentfrom the first surface.
 22. The method of claim 21, wherein the firstportion of the conductive layer and second portion of the conductivelayer are each removed using a laser oriented perpendicular to the firstsurface and parallel to the second surface.
 23. The method of claim 20,further including removing the first portion of the conductive layersimultaneously with removing the second portion of the conductive layer.24. The method of claim 20, further including rotating the semiconductorpackage after removing the first portion of the conductive layer andbefore removing the second portion of the conductive layer.
 25. Themethod of claim 20, wherein the first portion of the conductive layerand second portion of the conductive layer are discontinuous.